A performance measure for WCDMA serial interference cancellation receivers

Serial interference cancellation (SIC) is a promising receiver structure for enhancing the uplink capacity of CDMA-based cellular systems. It can be implemented in practice with low complexity compared to other multiuser detection techniques. In this work, we define and calculate a new performance measure for SIC receivers. The proposed measure is denoted as the interference cancellation factor and models the amount of residual interference after applying SIC. The adopted system model resembles the WCDMA FDD mode of UMTS. We show that the amount of residual interference is a function of the receiver structure, a set of system parameters, and the channel model. Performance results are presented and compared with Monte-Carlo simulations. Using the calculated factor, it can for example be shown that applying SIC with soft detection and two cancellation stages can nearly double the uplink user capacity of a WCDMA cellular system.